The present invention relates generally to small peptide-based constructs that have 8 to 15 amino acid moieties. The sequences of these peptide-based constructs are designed and prepared based on a reverse subsequence (99-85) derived from amino acids identified and selected from Domain II of bactericidal/permeability-increasing protein (BPI). The invention further relates to therapeutic uses of such peptide-based constructs due to their properties of heparin binding and neutralization, inhibition of endothelial cell proliferation and/or inhibition of angiogenesis, e.g., inhibition of in vivo neovascularization, including in models of chronic inflammatory disease states and metastatic tumors.
Bactericidal/permeability-increasing protein (BPI) is a protein isolated from the granules of mammalian polymorphonuclear neutrophils (PMNs), which are blood cells essential in defending a mammal against invading microorganisms. Human BPI has been isolated from PMNs by acid extraction combined with either ion exchange chromatography (Elsbach, 1979, J. Biol. Chem. 25: 11000) or E. coli affinity chromatography (Weiss et al., 1987, Blood 69: 652), and has bactericidal activity against gram-negative bacteria. The molecular weight of human BPI is approximately 55,000 daltons (55 kD). The amino acid sequence of the entire human BPI protein and the nucleic acid sequence of DNA encoding BPI, have been reported by Gray et al., 1989, J. Biol. Chem. 264: 9505 (see FIG. 1 in Gray et al.). The Gray et al. DNA and amino acid sequences are set out in SEQ ID NOS: 12 and 13 hereto.
The bactericidal effect of BPI was originally reported to be highly specific to sensitive gram-negative species. The precise mechanism by which BPI kills gram-negative bacteria is not yet known, but it is known that BPI must first attach to the surface of susceptible gram-negative bacteria. This initial binding of BPI to the bacteria involves electrostatic interactions between BPI, which is a basic (ie., positively charged) protein, and negatively charged sites on lipopolysaccharides (LPS). LPS is also known as xe2x80x9cendotoxinxe2x80x9d because of the potent inflammatory response that it stimulates. LPS induces the release of mediators by host inflammatory cells which may ultimately result in irreversible endotoxic shock. BPI binds to Lipid A, the most toxic and most biologically active component of LPS.
BPI is also capable of neutralizing the endotoxic properties of LPS to which it binds. Because of its gram-negative bactericidal properties and its ability to bind to and neutralize LPS, BPI can be utilized for the treatment of mammals suffering from diseases and conditions initiated by infection with gram-negative bacteria whether the bacteria infect from outside the host or the bacteria infect from within the host (i.e., gut-derived), including conditions of bacteremia, endotoxemia, and sepsis. These properties of BPI make BPI particularly useful and advantageous for such therapeutic administration.
A proteolytic fragment corresponding to the amino-terminal portion of human BPI possesses the LPS binding and neutralizing activities and antibacterial activity of BPI holoprotein. In contrast to the amino-terminal portion, the carboxyl-terminal region of isolated human BPI displays only slightly detectable antibacterial activity and some endotoxin neutralizing activity (Ooi et al., 1991, J. Exp. Med. 174: 649). One BPI amino-terminal fragment, referred to as xe2x80x9crBPI23xe2x80x9d (see Gazzano-Santoro et al., 1992, Infect. Immun. 60: 4754-4761) has been produced by recombinant means as a 23 kD protein and comprises an expression product of DNA encoding the first 199 amino acid residues of the human BPI holoprotein taken from Gray et al., supra, except that valine at position 151 is specified by GTG rather than GTC and residue 185 is glutamic acid (specified by GAG) rather than lysine (specified by AAG). Recombinant holoprotein, also referred to as rBPI, has also been produced having the sequence set out in SEQ ID NOS: 12 and 13 taken from Gray et al., supra, with the exceptions noted for rBPI23. An N-terminal fragment analog designated rBPI21 or rBPI2xcex94cys or rBPI (1-193) ala132 has been described in co-owned U.S. Pat. No. 5,420,019 and corresponding International Publication No. WO 94/18323 (PCT/US94/01235). This analog comprises the first 193 amino acids of BPI holoprotein as set out in SEQ ID NOS: 12 and 13 but wherein the cysteine at residue number 132 is substituted with alanine, and with the exceptions noted for rBPI23. rBPI23, as well as the cysteine substitution analog designated rBPI21, have been introduced into human clinical trials. Proinflammatory responses to endotoxin were significantly ameliorated when rBPI23 was administered in humans challenged with endotoxin. (See, e.g., co-owned U.S. Pat. Nos. 5,643,875 and 5,753,620 and corresponding International Publication No. WO 95/19784 (PCT/US95/01151). In addition, rBPI21 was administered in humans with meningococcemia and hemorrhage due to trauma. (See, e.g., U.S. Pate. No. 5,888,977 and corresponding International Publication No. WO 97/42966 (PCT/US97/08016) and U.S. Pat. No. 5,756,464 and corresponding International Publication No. WO 97/44056 (PCT/US97/08941).
Other endotoxin binding and neutralizing proteins and peptides are known in the art. One example is Limulus antilipopolysaccharide factor (LALF) from horseshoe crab amebocytes (Warren et al., 1992, Infect. Immunol. 60: 2506-2513). Another example is a cyclic, cationic lipopeptide from Bacillus polymyxa, termed Polymyxin B1. Polymyxin B1 is composed of six xcex1,xcex3-diaminobutyric acid residues, one D-phenylalanine, one leucine, one threonine and a 6-methyloctanoyl moiety (Morrison and Jacobs, 1976, Immunochem. 13: 813-818) and is also bactericidal. Polymyxin analogues lacking the fatty acid moiety are also known, which analogues retain LPS binding capacity but are without appreciable bactericidal activity (Danner et al., 1989, Antimicrob. Agents Chemother. 33: 1428-1434). Similar properties have also been found with synthetic cyclized polymyxin analogues (Rustici et al., 1993, Science 259: 361-365).
Known antibacterial peptides include cecropins and magainins. The cecropins are a family of antibacterial peptides found in the hemolymph of lepidopteran insects (Wade et al., 1990, Proc. Natl. Acad. Sci. USA 87: 4761-4765), and the magainins are a family of antibacterial peptides found in Xenopus skin and gastric mucosa (Zasloffet al., 1988, Proc. Natl. Acad. Sci. USA 85: 910-913). These peptides are linear and range from about 20 to about 40 amino acids in length. A less active mammalian cecropin has been reported from porcine intestinal mucosa, cecropin P1 (Boman et al., 1993, Infect. Immun. 61: 2978-2984). The cecropins are generally reported to be more potent than the magainins in bactericidal activity and appear to have less mammalian cell cytotoxicity. The cecropins and magainins are characterized by a continuous, amphipathic xcex1-helical region which is necessary for bactericidal activity. The most potent of the cecropins identified to date is cecropin A. The sequence of the first ten amino acids of the cecropin A has some homology with the BPI amino acid sequence 90-99 but does not share the motif of charged and uncharged amino acids specified by the BPI amino acid sequence 90-99. In addition, the other 27 amino acids of cecropin A are necessary for maximal bactericidal activity and there is no homology with BPI for those 27 amino acids. The magainins have minimal homology with the BPI amino acid sequence 90-99.
Of interest to the present application are the disclosures in PCT International Application PCT/US91/05758 [WO 92/03535] relating to compositions comprising BPI and an anionic compound, which compositions are said to exhibit (1) no bactericidal activity and (2) endotoxin neutralizing activity. Anionic compounds are preferably a protein such as serum albumin but can also be a polysaccharide such as heparin. In addition, Weiss et al., 1975, J. Clin. Invest. 55: 33-42, disclose that heparin sulfate and LPS block expression of the permeability-increasing activity of BPI. However, neither reference discloses that BPI actually binds to and/or neutralizes the biologic activities of heparin. Heparin binding does not necessarily imply heparin neutralization. For example, a family of heparin binding growth factors (HBGF) requires heparin as a cofactor to elicit a biological response. Examples of HBGF""s include: fibroblast growth factors (FGF-1, FGF-2) and endothelial cell growth factors (ECGF-1, ECGF-2). Antithrombin III inhibition of clotting cascade proteases is another example of a heparin binding protein that requires heparin for activity and clearly does not neutralize heparin. Heparin binding proteins that do neutralize heparin (e.g., platelet factor IV, protamine, and thrombospondin) are generally inhibitory of the activities induced by heparin binding proteins that use heparin as a cofactor.
Of particular interest to the present application are the heparin-related activities of BPI protein products. Specifically, BPI protein products have been shown to have heparin binding and heparin neutralization activities in co-assigned U.S. Pat. Nos. 5,348,942; 5,639,727; 5,807,818; 5,837,678; 5,854,214 and corresponding International Publication No. WO 94/02401 (PCT/US94/02401). For example, rBPI23 was shown to have high affinity for heparin (see also, Little et al., 1994, J Biol. Chem. 269: 1865-1872, and has been administered in humans to neutralize heparin (see, e.g. U.S. Pat. No. 5,348,942). These heparin binding and neutralization activities of BPI protein products are significant due to the importance of current clinical uses of heparin. Heparin is commonly administered in doses of up to 400 U/kg during surgical procedures such as cardiopulmonary bypass, cardiac catheterization and hemodialysis procedures in order to prevent blood coagulation during such procedures. When heparin is administered for anticoagulant effects during surgery, it is an important aspect of post-surgical therapy that the effects of heparin are promptly neutralized so that normal coagulation function can be restored. Currently, protamine is used to neutralize heparin. Protamines are a class of simple, arginine-rich, strongly basic, low molecular weight proteins. Administered alone, protamines (usually in the form of protamine sulfate) have anti-coagulant effects. When administered in the presence of heparin, a stable complex is formed and the anticoagulant activity of both drugs is lost. However, significant hypotensive and anaphylactoid effects of protamine have limited its clinical utility. Thus, due to its heparin binding and neutralization activities, BPI protein products have potential utility as a substitute for protamine in heparin neutralization in a clinical context without the deleterious side-effects which have limited the usefulness of the protamines. The additional antibacterial and anti-endotoxin effects of such BPI protein products would also be useful and advantageous in post-surgical heparin neutralization compared with protamine.
Additionally of particular interest, is the activity of BPI protein products to inhibit angiogenesis due in part to their heparin binding and neutralization activities (see, e.g., U.S. Pat. Nos. 5,807,818 and 5,837,678 and corresponding International Publication No. WO 94/02401 (PCT/US94/02401). Angiogenesis, the growth of new blood vessels (neovascularization) is a complex phenomenon that involves growth factors, most of which have heparin as a co-factor. In adults, angiogenic growth factors are released as a result of vascular trauma (wound healing), immune stimuli (autoimmune disease), inflammatory mediators (prostaglandins) or from tumor cells. These factors induce proliferation of endothelial cells (which is necessary for angiogenesis) via a heparin-dependent receptor binding mechanism (see Yayon et al., 1991, Cell 64: 841-848). Angiogenesis is also associated with a number of other pathological conditions, including the growth, proliferation, and metastasis of various tumors; diabetic retinopathy, macular degeneration, retrolental fibroplasia, neovascular glaucoma, psoriasis, angiofibromas, immune and non-immune inflammation including rheumatoid arthritis, capillary proliferation within atherosclerotic plaques, hemangiomas, endometriosis and Kaposi""s sarcoma. Thus, it would be desirable to inhibit angiogenesis in these and other instances, and the heparin binding and neutralization activities of BPI protein products, including peptides derived from or based on BPI, are useful to that end.
Heparin binding proteins fall into at least two classes. The first class consists of those proteins that utilize heparin as a co-factor in eliciting a specific response. These proteins include heparin-dependent growth factors (e.g., basic fibroblast growth factor, acidic fibroblast growth factor and vascular endothelial cell growth factor) which play a major role in angiogenesis. The second class includes proteins that neutralize the heparin-dependent response. BPI protein products, including peptides derived from BPI, have been identified as heparin neutralizing and anti-angiogenic agents. Several other heparin neutralizing proteins are also known to inhibit angiogenesis. For example, protamine is known to inhibit tumor-associated angiogenesis and subsequent tumor growth [see Folkman et al., 1992, Inflammation: Basic Principles and Clinical Correlates, 2d ed., (Galin et al., eds., Review Press, N.Y.), Ch. 40, pp. 821-839]. A second heparin neutralizing protein, platelet factor IV, also inhibits angiogenesis (i.e., is angiostatic). Another known angiogenesis inhibitor, thrombospondin, binds to heparin with a repeating serine/tryptophan motif instead of a basic amino acid motif (see Guo et al., 1992, J Biol. Chem. 267: 19349-19355). Murine endostatin is also reported to bind heparin and inhibit angiogenesis (see, e.g., Hohenester et al., 1998, Embo J. 17: 1656-1664; O""Reilly et al., 1997, Cell 88: 277-285).
Another utility of BPI protein products involves pathological conditions associated with chronic inflammation, which is usually accompanied by angiogenesis (see, e.g., U.S. Pat. No. 5,639,727). One example of a human disease related to chronic inflammation is arthritis, which involves inflammation of peripheral joints. In rheumatoid arthritis, the inflammation is autoimmune, while in reactive arthritis, inflammation is hypothesized to be associated with initial infection of the synovial tissue with pyogenic bacteria or other infectious agents followed by aseptic chronic inflammation in susceptible individuals. Folkman et al., 1992, supra, have also noted that many types of arthritis progress from a stage dominated by an inflammatory infiltrate in the joint to a later stage in which a neovascular pannus invades the joint and begins to destroy cartilage. While it is unclear whether angiogenesis in arthritis is a causative component of the disease or an epiphenomenon, there is evidence that angiogenesis is necessary for the maintenance of synovitis in rheumatoid arthritis. One known angiogenesis inhibitor, AGM1470, has been shown to prevent the onset of arthritis and to inhibit established arthritis in collagen-induced arthritis models (Peacock et al., 1992, J. Exp. Med. 175:1135-1138). While nonsteroidal anti-inflammatory drugs, corticosteroids and other therapies have provided treatment improvements for relief of arthritis, there remains a need in the art for more effective therapies for arthritis and other inflammatory diseases.
Many additional utilities of BPI protein products, including rBPI23 and rBPI21, have been described due to the wide variety of biological activities of these products. For example, BPI protein products are bactericidal for gram-negative bacteria, as described in U.S. Pat. Nos. 5,198,541 and 5,523,288. International Publication No. WO 94/20130 proposes methods for treating subjects suffering from an infection (e.g. gastrointestinal) with a species from the gram-negative bacterial genus Helicobacter with BPI protein products. BPI protein products also enhance the effectiveness of antibiotic therapy in gram-negative bacterial infections, as described in U.S. Pat. No. 5,523,288 and International Publication No. WO 95/08344 (PCT/US94/11255). BPI protein products are also bactericidal for gram-positive bacteria and mycoplasma, and enhance the effectiveness of antibiotics in gram-positive bacterial infections, as described in U.S. Pat. Nos. 5,578,572 and 5,783,561 and International Publication No. WO 95/19180 (PCT/US95/00656). BPI protein products exhibit anti-fungal activity, and enhance the activity of other anti-fungal agents, as described in U.S. Pat. No. 5,627,153 and International Publication No. WO 95/19179 (PCT/US95/00498), and further as described for anti-fungal peptides in U.S. Pat. No. 5,858,974, which is in turn a continuation-in-part of U.S. application Ser. No. 08/504,841, abandoned, and corresponding International Publication Nos. WO 96/08509 (PCT/US95/09262) and WO 97/04008 (PCT/US96/03845). BPI protein products exhibit anti-protozoan activity, as described in U.S. Pat. No. 5,646,114 and International Publication No. WO 96/01647 (PCT/US95/08624). BPI protein products exhibit anti-chlamydial activity, as described in co-owned U.S. Pat. No. 5,888,973 and WO 98/06415 (PCT/US97/13810). Finally, BPI protein products exhibit anti-mycobacterial activity, as described in co-owned, co-pending U.S. application Ser. No. 08/626,646, issued as U.S. Pat. No. 6,214,739, which is in turn a continuation of U.S. application Ser. No. 08/285,803, abandoned, which is in turn a continuation-in-part of U.S. application Ser. No. 08/031,145, abandoned, and corresponding International Publication No. WO94/20129 (PCT/US94/02463).
BPI protein products are also useful for treatment of specific disease conditions, such as meningococcemia in humans (as described in co-owned U.S. application Ser. No. 08/644,287, abandoned, and U.S. Pat. No. 5,888,977 and International Publication No. WO97/42966 (PCT/US97/08016), hemorrhagic trauma in humans, (as described in U.S. Pat. No. 5,756,464, U.S. application Ser. No. 08/862,785, issued as U.S. Pat. No. 5,945,399, and corresponding International Publication No. WO 97/44056 (PCT/US97/08941), burn injury (as described in U.S. Pat. No. 5,494,896) ischemia/reperfusion injury (as described in U.S. Pat. No. 5,578,568), and liver resection (as described in co-owned, co-pending U.S. application Ser. No. 08/582,230, abandoned which is in turn a continuation of U.S. application Ser. No. 08/318,357, abandoned, which is in turn a continuation-in-part of U.S. application Ser. No. 08/132,510, abandoned, and corresponding International Publication No. WO 95/10297 (PCT/US94/11404).
BPI protein products are also useful in antithrombotic methods, as described in U.S. Pat. No. 5,741,779 and U.S. application Ser. No. 09/063,465, issued as U.S. Pat. No. 5,935,930, and corresponding International Publication No. WO 97/42967 (PCT/US7/08017).
There continues to exist a need in the art for new products that have one or more of the biological activities of BPI protein products, particularly products for use as heparin binding and neutralizing agents and for the inhibition of endothelial cell proliferation as well as inhibition of angiogenesis (normal or pathological). Advantageous therapeutic products that are peptide-based would ideally comprise small active sequences that are serum stable.
This invention provides compounds and compositions of small peptide-based constructs having an 8-15 amino acid moiety sequence that is derived from or based on reverse subsequences from functional domain II (amino acids 65-99) of BPI and having at least one of the heparin-related biological activities of BPI, such as heparin binding, heparin neutralization, inhibition of endothelial cell proliferation and/or inhibition of angiogenesis. A reverse (or retro) sequence is inverted from the original (e.g., if an original sequence is A-B-C, the inverted sequence is C-B-A). Such peptide-based constructs according to the invention have reverse subsequences that consist of a minimum core sequence based on an amino acid motif derived from amino acids 99-92 of BPI. In a preferred embodiment the reverse subsequence is a substituted subsequence (for example, amino acids 99-92, 99-91, 99-90, 99-89, 99-88, 99-87, 99-86, or 99-85 wherein the substitutions are at 95 and 91).
Constructs (or compositions) according to the invention include those that are 8-15 moieties in length having heparin binding, heparin neutralizing, endothelial cell proliferation inhibiting, or antiangiogenic properties and comprise: a sequence having the formula: xcex1-"khgr"-"khgr"-xcex1-"khgr"-xcex2-"khgr"-xcex1-R. In the sequence, xcex1 is a hydrophilic basic amino acid moiety selected from the group consisting of lysine, arginine, histidine, ornithine, diaminobutyric acid, citrulline, or para-amino phenylalanine; xcex2 is a hydrophilic neutral amino acid moiety selected from the group consisting of asparagine, glutamine, serine, threonine, tyrosine, hydroxyproline, or 7-hydroxy-tetrahydroisoquinoline carboxylic acid; "khgr" is a hydrophobic amino acid moiety selected from the group consisting of alanine, naphthylalanine, biphenylalanine, valine, leucine, isoleucine, proline, hydroxyproline, phenylalanine, tryptophan, methionine, glycine, cyclohexylalanine, amino-isobutyric acid, norvaline, norleucine, tert-leucine, tetrahydroisoquinoline carboxylic acid, pipecolic acid, phenylglycine, homophenylalanine, cyclohexylglycine, dehydroleucine, 2,2-diethylglycine, 1-amino-1-cyclopentane carboxylic acid, 1-amino-1-cyclohexane carboxylic acid, amino-benzoic acid, amino-naphthyl carboxylic acid, 7-amino butyric acid, beta-alanine, difluorophenylalanine, fluorophenylalanine, nipecotic acid, aminobutyric acid, thienyl-alanine, t-butyl-glycine; and R is a moiety selected from the group consisting of -"khgr", -"khgr"-xcex1, -"khgr"-xcex1-"khgr", "khgr"-xcex1-"khgr"-xcex2, -"khgr"-xcex1-"khgr"-xcex2-"khgr", -"khgr"-xcex1-"khgr"-xcex2-"khgr"-xcex1, -"khgr"-xcex1-"khgr"-xcex2-"khgr"-xcex1-"khgr", -"khgr"-xcex2-"khgr"-"khgr"-xcex2-"khgr", -NH2, -"khgr"-NH2, -"khgr"-xcex1-NH2, -"khgr"-xcex1-"khgr"-NH2, -"khgr"-xcex1-"khgr"-xcex2-NH2, -"khgr"-xcex1-"khgr"-xcex2-"khgr"-NH2, -"khgr"-xcex1-"khgr"-xcex2-"khgr"-xcex1-NH2, -"khgr"-xcex1-"khgr"-xcex2-"khgr"-xcex1-"khgr"-NH2, -"khgr"-xcex2-"khgr"-"khgr"-xcex2-"khgr"-NH2.
The invention also provides a composition of 8-15 amino acid moieties consecutively linked by peptide bonds, said composition having heparin binding properties and comprising a sequence of the formula:
KLFR(naph-A)QAR1
wherein R1 is selected from the group consisting of K (SEQ ID NO: 8), K(naph-A) (SEQ ID NO: 7), K(naph-A)K (SEQ ID NO: 6), K(naph-A)KG (SEQ ID NO: 5), K(naph-A)KGS (SEQ ID NO: 4), K(naph-A)KGSI (SEQ ID NO: 3), K(naph-A)KGSIK (SEQ ID NO: 2) and K(naph-A)KGSIKI (SEQ ID NO: 1); and
wherein the carboxyl terminal group is amidated or nonamidated, and conservative substitution variants thereof having heparin binding properties. Preferably, the variants comprise at least one conservative substitution.
The compositions of the invention preferably comprise compositions wherein the first two amino-terminal amino acid moieties are D-amino acid moieties and the last two carboxy-terminal amino acid moieties are D-amino acid moieties.
Also provided are methods of neutralizing heparin in a mammal that has been administered an exogenous heparin compound (including heparin or heparinoid substances, such as low molecular weight heparins) comprising the step of administering to said mammal an amount of the composition of the invention effective to neutralize the anticoagulant effect of the exogenous heparin compound, preferably in an amount effective to return the clotting time of said mammal to normal; methods of inhibiting endothelial cell proliferation in a mammal in need thereof by administering to said mammal an amount of the compositions of the invention effective to inhibit endothelial cell proliferation;
methods of inhibiting angiogenesis in a mammal in need thereof by administering to said mammal an amount of such compositions effective to inhibit angiogenesis, including angiogenesis in the eye; methods of treating a mammal suffering from a disorder involving angiogenesis, including a chronic inflammatory disease, such as rheumatoid or reactive arthritis, and including the growth, proliferation or metastasis of tumor cells.
Additional properties or activities of such constructs may include LPS binding, LPS neutralization, and/or antimicrobial activity and/or any other previously known activity or property of BPI protein products. Although three functional domains of BPI were previously reported and include: domain I, encompassing the amino acid sequence of BPI from about amino acid 17 to about amino acid 45; domain II, encompassing the amino acid sequence of BPI from about amino acid 65 to about amino acid 99; and domain III, encompassing the amino acid sequence of BPI from about amino acid 142 to about amino acid 169, biologically active reverse (or retro) sequences have not been previously reported based on subsequences of domain II. Thus, such peptide-based reverse (retro) sequence constructs according to the invention, which preferably comprise selected D-amino acid moieties, are particularly useful as therapeutic agents.
The present invention provides biologically active novel constructs (or compositions) having a sequence of 8 to 15 amino acid moieties that is derived from a reverse subsequence of functional domain II of BPI (i.e., peptide-based constructs). Preferred are constructs with sequences that contain D-amino acid moieties. Particularly preferred are constructs with sequences where the D-amino acid moieties are positioned as the first two and last two moieties of the sequence. Such constructs are particularly useful for the treatment of heparin-related or heparin-mediated disorders, diseases or conditions. xe2x80x9cTreatmentxe2x80x9d as used herein encompasses both prophylactic and therapeutic treatment. Treatment of mammals, including humans, is contemplated.
As used herein, xe2x80x9camino acid moietyxe2x80x9d includes typical and atypical amino acid compounds (including derivatized amino acids and amino acid analogs). xe2x80x9cConservativexe2x80x9d substitutions of one amino acid for another are substitutions of amino acids having similar structural and/or chemical properties, and are generally based on similarities in polarity, charge, hydrophobicity, hydrophilicity and/or the amphipathic nature of the residues involved. Hydrophobic, polar neutral and polar basic amino acids include those described above for xcex1, xcex2 and "khgr". Polar acidic amino acids include aspartic acid and glutamic acid. As a general rule, as the similarity between the amino acids being substituted decreases, the likelihood that the substitution will affect activity increases.
For the purposes of this invention, the term xe2x80x9cfunctional domainxe2x80x9d is intended to designate a region of the amino acid sequence of BPI that exhibits one or more of the biological activities of BPI. These functional domains of BPI were defined by the activities of proteolytic cleavage fragments, overlapping 15-mer peptides and other synthetic peptides. Domain I has been defined as the amino acid sequence of BPI comprising from about amino acid 17 to about amino acid 45. Initial peptides based on this domain were moderately active in both the inhibition of LPS-induced LAL activity and in heparin binding assays, and did not exhibit significant antibacterial activity. Domain II has been defined as the amino acid sequence of BPI comprising from about amino acid 65 to about amino acid 99. Initial peptides based on this domain exhibited high LPS and heparin binding capacity and exhibited significant antibacterial activity. Domain III has been defined as the amino acid sequence of BPI comprising from about amino acid 142 to about amino acid 169. Initial peptides based on this domain exhibited high LPS and heparin binding activity, and exhibited surprising antimicrobial activity, including antifungal and antibacterial (including, e.g., anti-gram-positive and anti-gram-negative) activity.
For purposes of this invention, the term xe2x80x9cbiological activity of BPIxe2x80x9d is intended to include, but is not limited to one or more of the biological activities or properties of a human bactericidal/permeability-increasing (BPI) protein product, including, for example, a recombinant BPI holoprotein such rBPI (SEQ ID NO: 13), an amino-terminal fragment of BPI such as rBPI23, and analogs that are mutated amino-terminal fragments of BPI such as rBPI21xcex94cys and including any of the known activities of the BPI protein products discussed above. Specifically included is a biological activity of any peptide-based construct of this invention that is between 0.1 and 10 times the activity of BPI or of a corresponding peptide encompassing a corresponding functional domain of BPI. The term xe2x80x9cbiological activity of BPIxe2x80x9d is intended to include, but is not limited to an activity of heparin binding, heparin neutralization, inhibition of endothelial cell proliferation or inhibition of angiogenesis (e.g., inhibition of in vivo neovascularization such as that associated with metastatic tumors and chronic inflammatory disease states). Also included in this definition of xe2x80x9cbiological activity of BPIxe2x80x9d is an activity of LPS binding, LPS neutralization, or antimicrobial activity. Also expressly included in this definition of the xe2x80x9cbiological activity of BPIxe2x80x9d is a biological activity, for example antimicrobial activity, that is qualitatively different than the activity of BPI or the corresponding peptide encompassing the entire corresponding domain of BPI. For example, such qualitative differences include differences in the spectrum of bacteria or other microorganisms against which the peptide is effective, relative to the amino acid sequence of the corresponding functional domain of BPI. This definition thus encompasses antimicrobial activities, such as antibacterial activity (e.g. against gram-positive bacteria, mycobacteria and chlamydia) and antifungal activity (e.g., against species of Candida, Aspergillus, Cryptococcus, Histoplasma, Coccidioides, Blastomyces, Basidiobolus, Conidiobolus, Rhizopus, Rhizomucor, Mucor, Absidia, Mortierella, Cunninghamella, Saksenaea, Fusapium, Trichophyton, Trichosporon, Microsporum, Epidernmophyton, Scytalidium, Malassezia, Actinomyceies, Sporothrix and Penicillium).
The invention provides exemplary peptide-based constructs each of which has a sequence that is derived from or based on reverse substituted subsequences from functional domain II of human BPI (e.g., amino acids 99-92, 99-91, 99-90, 99-89, 99-88, 99-87, 99-86, or 99-85 wherein the substitutions are at 75 and 91)). Embodiments of such constructs include the following exemplary domain II basic constructs [single-letter abbreviations for amino acids can be found in G. Zubay, Biochemistry (2d. ed.), 1988 (MacMillen Publishing: N.Y.), p.33]:
As used herein, xe2x80x9cBPI protein productxe2x80x9d includes naturally and recombinantly produced BPI protein; natural, synthetic, and recombinant biologically active polypeptide fragments of BPI protein; biologically active polypeptide variants of BPI protein or fragments thereof, including hybrid fusion proteins and dimers; biologically active polypeptide analogs of BPI protein or fragments or variants thereof, including cysteine-substituted analogs; and BPI-derived peptides. BPI protein products may be generated and/or isolated by any means known in the art. U.S. Pat. No. 5,198,541, discloses recombinant genes encoding, and methods for expression of, BPI proteins including recombinant BPI holoprotein, referred to as rBPI and recombinant fragments of BPI. U.S. Pat. No. 5,439,807 and corresponding International Publication No. WO 93/23540 (PCT/US93/04752), disclose novel methods for the purification of recombinant BPI protein products expressed in and secreted from genetically transformed mammalian host cells in culture and discloses how one may produce large quantities of recombinant BPI products suitable for incorporation into stable, homogeneous pharmaceutical preparations.
Biologically active fragments of BPI (BPI fragments) include biologically active molecules that have the same or similar amino acid sequence as a natural human BPI holoprotein, except that the fragment molecule lacks amino-terminal amino acids, internal amino acids, and/or carboxy-terminal amino acids of the holoprotein. Nonlimiting examples of such fragments include an N-terminal fragment of natural human BPI of approximately 25 kD, described in Ooi et al., 1991, J. Exp. Med., 174:649, and the recombinant expression product of DNA encoding N-terminal amino acids from 1 to about 193 to 199 of natural human BPI, described in Gazzano-Santoro et al., 1992, Infect. Immun. 60:4754-4761, and referred to as rBPI23. In that publication, an expression vector was used as a source of DNA encoding a recombinant expression product (rBPI23) having the 31-residue signal sequence and the first 199 amino acids of the N-terminus of the mature human BPI, as set out in FIG. 1 of Gray et al., supra, except that valine at position 151 is specified by GTG rather than GTC and residue 185 is glutamic acid (specified by GAG) rather than lysine (specified by AAG). Recombinant holoprotein (rBPI) has also been produced having the sequence (SEQ ID NOS: 12 and 13) set out in FIG. 1 of Gray et al., supra, with the exceptions noted for rBPI23 and with the exception that residue 417 is alanine (specified by GCT) rather than valine (specified by GTT). An analog of an N-terminal fragment consisting of residues 10-193 of BPI has been described in co-owned, co-pending U.S. application Ser. No. 09/099,725, issued as U.S. Pat. No. 6,013,631. Other examples include dimeric forms of BPI fragments, as described in U.S. Pat. No. 5,447,913 and corresponding International Publication No. WO 95/24209 (PCT/US95/03125).
Biologically active variants of BPI (BPI variants) include but are not limited to recombinant hybrid fusion proteins, comprising BPI holoprotein or biologically active fragment thereof and at least a portion of at least one other polypeptide, and dimeric forms of BPI variants. Examples of such hybrid fusion proteins and dimeric forms are described in U.S. Pat. No. 5,643,570 and corresponding International Publication No. WO 93/23434 (PCT/US93/04754), and include hybrid fusion proteins comprising, at the amino-terminal end, a BPI protein or a biologically active fragment thereof and, at the carboxy-terminal end, at least one constant domain of an immunoglobulin heavy chain or allelic variant thereof.
Biologically active analogs of BPI (BPI analogs) include but are not limited to BPI protein products wherein one or more amino acid residues have been replaced by a different amino acid. For example, U.S. Pat. No. 5,420,019 and corresponding International Publication No. WO 94/18323 (PCT/US94/01235), discloses polypeptide analogs of BPI and BPI fragments wherein a cysteine residue is replaced by a different amino acid. A stable BPI protein product described by this application is the expression product of DNA encoding from amino acid 1 to approximately 193 or 199 of the N-terminal amino acids of BPI holoprotein, but wherein the cysteine at residue number 132 is substituted with alanine and is designated rBPI21xcex94cys or rBPI21. Production of this N-terminal analog of BPI, rBPI21, has been described in Horwitz et al., 1996, Protein Expression Purification, 8:28-40. Similarly, a fragment consisting of residues 10-193 of BPI in which the cysteine at position 132 is replaced with an alanine (designated xe2x80x9crBPI(10-193)C132Axe2x80x9d or xe2x80x9crBPI(10-193)ala132xe2x80x9d) has been described in co-owned, co-pending U.S. application Ser. No. 09/099,725, issued as U.S. Pat. No. 6,013,631. Other examples include dimeric forms of BPI analogs; e.g. U.S. Pat. No. 5,447,913 and corresponding International Publication No. WO 95/24209 (PCT/US95/03125).
Other BPI protein products are peptides derived from or based on BPI produced by synthetic or recombinant means (BPI-derived peptides), such as those described in International Publication No. WO 97/04008 (PCT/US96/03845), which corresponds to U.S. Pat. No. 5,858,974 and International Publication No. WO 96/08509 (PCT/US95/09262), which corresponds to U.S. patent application Ser. No. 09/119,858, abandoned, and International Publication No. WO 95/19372 (PCT/US94/10427), which corresponds to U.S. Pat. Nos. 5,652,332 and 5,856,438, and International Publication No. WO94/20532 (PCT/US94/02465), which corresponds to U.S. Pat. No. 5,763,567 which is a continuation of U.S. Pat. No. 5,733,872, which is a continuation-in-part of U.S. application Ser. No. 08/183,222, abandoned, which is a continuation-in-part of U.S. application Ser. No. 08/093,202, abandoned, (corresponding to International Publication No. WO 94/20128 (PCT/US94/02401)), which is a continuation-in-part of U.S. Pat. No. 5,348,942, as well as International Publication No. WO 97/35009 (PCT/US97/05287), which corresponds to U.S. Pat. No. 5,851,802.
The present invention defines novel peptide-based constructs that may be defined as BPI protein products.
The administration of BPI protein products is preferably accomplished with a pharmaceutical composition comprising a BPI protein product and a pharmaceutically acceptable diluent, adjuvant, or carrier. The BPI protein product may be administered without or in conjunction with known surfactants or other therapeutic agents. A stable pharmaceutical composition containing BPI protein products (e.g., rBPI23) comprises the BPI protein product at a concentration of 1 mg/ml in citrate buffered saline (5 or 20 mM citrate, 150 mM NaCl, pH 5.0) comprising 0.1% by weight of poloxamer 188 (Pluronic F-68, BASF Wyandotte, Parsippany, N.J.) and 0.002% by weight of polysorbate 80 (Tween 80, ICI Americas Inc., Wilmington, Del.). Another stable pharmaceutical composition containing BPI protein products (e.g., rBPI21,) comprises the BPI protein product at a concentration of 2 mg/ml in 5 mM citrate, 150 mM NaCl, 0.2% poloxamer 188 and 0.002% polysorbate 80. Such preferred combinations are described in U.S. Pat. Nos. 5,488,034 and 5,696,090 and corresponding International Publication No. WO 94/17819 (PCT/US94/01239). As described in U.S. Pat. No. 5,912,228, which is in turn a continuation-in-part of U.S. application Ser. No. 08/530,599, abandoned, which is in turn a continuation-in-part of U.S. application Ser. No. 08/372,104, abandoned, and corresponding International Publication No. WO 96/21436 (PCT/US96/01095), other poloxamer formulations of BPI protein products with enhanced activity may be utilized. Peptide-based constructs may be formulated like other BPI protein products or may be formulated in saline or a physiological buffer.
Therapeutic compositions comprising BPI protein product (including the peptide-based constructs or compositions of the invention) may be administered systemically or topically. Systemic routes of administration include oral, intravenous, intramuscular or subcutaneous injection (including into a depot for long-term release), intraocular and retrobulbar, intrathecal, intraperitoneal (e.g. by intraperitoneal lavage), intrapulmonary (using powdered drug, or an aerosolized or nebulized drug solution), or transdermal. Topical routes include administration in the form of salves, ophthalmic drops, ear drops, or irrigation fluids (for, e.g., irrigation of wounds).
When given parenterally, BPI protein product compositions are generally injected in doses ranging from 1 xcexcg/kg to 100 mg/kg per day, preferably at doses ranging from 0.1 mg/kg to 20 mg/kg per day. The treatment may continue by continuous infusion or intermittent injection or infusion, at the same, reduced or increased dose per day for, e.g., 1 to 3 days, and additionally as determined by the treating physician.
Those skilled in the art can readily optimize effective dosages and administration regimens for therapeutic compositions comprising BPI protein product (including the constructs or compositions of the present invention), as determined by good medical practice and the clinical condition of the individual subject.
The constructs or compositions of the invention may be used in any of the therapeutic uses for which BPI products are known to be effective, including those described above. The constructs are particularly useful in methods for binding and neutralizing exogenous heparin, methods for inhibiting endothelial cell proliferation, treating disorders associated with endothelial cell proliferation, methods for inhibiting angiogenesis, and treating disorders associated with or involving angiogenesis.
Exogenous heparin compounds are commonly administered during surgical procedures requiring anticoagulation, such as cardiopulmonary bypass, cardiac catheterization or angioplasty, and hemodialysis. Exogenous heparin compounds are also administered to patients at risk of or suffering from thrombosis, e.g. patients suffering from deep venous thrombosis, acute myocardial infarction, stroke, or pulmonary embolism.
Angiogenesis-associated disorders are disorders in which angiogenesis plays a role in the initiation or progression of disease. Angiogenesis is involved in a number of conditions, illustrated below, and inhibition of angiogenesis is expected to be effective for treating any of these conditions (including inhibiting progression of the disease and ameliorating signs and symptoms of the disease).
Use of the constructs of the invention in preparation of a medicament for any of these therapeutic uses is also contemplated.
Angiogenesis is of considerable importance in cancer conditions because new vessel production is required to support the rapid growth of cancer cells. Inhibition of angiogenesis thus may promote tumor regression in adult and pediatric oncology, including reducing growth of solid tumors/malignancies, locally advanced tumors, metastatic cancer, human soft tissue sarcomas, cancer metastases, including lymphatic metastases, blood cell malignancies, effusion lymphomas (body cavity based lymphomas), lung cancer, including small cell carcinoma, non-small cell cancers, breast cancer, including small cell carcinoma and ductal carcinoma, gastrointestinal cancers, including stomach cancer, colon cancer, colorectal cancer, polyps associated with colorectal neoplasia, pancreatic cancer, liver cancer, urological cancers, including bladder cancer, prostate cancer, malignancies of the female genital tract, including ovarian carcinoma, uterine endometrial cancers, and solid tumors in the ovarian follicle, kidney cancer, including renal cell carcinoma, brain cancer, including intrinsic brain tumors, neuroblastoma, astrocytic brain tumors, gliomas, metastatic tumor cell invasion in the central nervous system, bone cancers, including osteomas, skin cancers, including malignant melanoma, tumor progression of human skin keratinocytes, and squamous cell cancer, hemangiopericytoma, and Kaposi""s sarcoma.
Angiogenesis also plays a role in chronic inflammation, including chronic pancreatitis, dermatosis associated with chronic inflammation, including psoriasis, cirrhosis, asthma, multiple sclerosis, arthritis, including rheumatoid arthritis, reactive arthritis and chronic inflammatory arthritis, autoimmune disorders, including vasculitis, glomerulonephritis, experimental allergic encephalomyelitis (EAE), lupus, myasthenia gravis, ulcerative colitis, Crohn""s disease, inflammatory bowel disease, chronic inflammation associated with hemodialysis, granulocyte transfusion associated syndrome; rejection reactions after allograft and xenograft transplantation, including graft versus host disease; and other chronic inflammatory disorders.
Angiogenesis in the eye is involved in ocular neovascularization, proliferative retinopathy, retrolental fibraplasia, macular degeneration, neovascular glaucoma and diabetic ocular disease, in particular, diabetic iris neovascularization and retinopathy.
Coronary atheroma are highly vascularized by a fragile capillary network, and rupture of these newly formed capillaries when they are exposed to high intravascular pressures may lead to hemorrhage into atherosclerotic plaques and coronary occlusion. Inhibition of angiogenesis thus may reduce the growth of atherosclerotic plaques and may be useful in the treatment of atherosclerosis, ischemic heart disease, myocardial infarction, coronary heart disease, restenosis, particularly following balloon angiography, neointimal hyperplasia, disruption of intercellular junctions in vascular endothelium, hypertension, vessel injury, arterial ischemia, arterial stenosis, peripheral vascular disease, stroke
Angiogenesis also occurs during the female reproductive cycle and is involved in endometriosis, uterine fibroids, other conditions associated with dysfunctional vascular proliferation (including endometrial microvascular growth) during the female reproductive cycle.
Angiogenesis is also involved in abnormal vascular growth, including cerebral arteriovenous malformations (AVMs), angiofibronas, and hemangionas.
Concurrent administration of other therapeutic agents appropriate for the condition being treated (e.g., other agents that inhibit angiogenesis or cancer therapeutic agents if indicated) is also contemplated.
xe2x80x9cConcurrent administration,xe2x80x9d or xe2x80x9cco-administration,xe2x80x9d as used herein includes administration of the agents, in conjunction or combination, together, or before or after each other. The BPI protein product and second agent(s) may be administered by different routes. For example, the BPI protein product may be administered intravenously while the second agent(s) is(are) administered intravenously, intramuscularly, subcutaneously, orally or intraperitoneally. The BPI protein product and second agent(s) may be given sequentially in the same intravenous line or may be given in different intravenous lines. Alternatively, the BPI protein product may be administered in a special form for gastric delivery, while the second agent(s) is(are) administered, e.g., orally. The formulated BPI protein product and second agent(s) may be administered simultaneously or sequentially, as long as they are given in a manner sufficient to allow all agents to achieve effective concentrations at the site of action.
Other aspects and advantages of the present invention will be understood upon consideration of the following illustrative examples wherein Example 1 addresses preparation and purification of peptide-based constructs; Example 2 addresses in vitro activity of peptide-based constructs in an endothelial cell proliferation assay; Example 3 addresses in vivo testing of the anti-angiogenic activities of peptide-based constructs; Example 4 addresses the in vivo testing of peptide-based constructs in models of chronic inflammatory disease states; Example addresses testing of peptide-based constructs in a malignant melanoma metastasis model; Example 6 addresses the in vitro testing of peptide-based constructs in oral absorption screening assays; Example 7 addresses the in vivo testing of peptide-based constructs for oral absorption; Example 8 addresses in vivo testing of peptide-based constructs for oral activity; and Example 9 addresses the in vitro and in vivo testing of peptide-based constructs in retinal neovascularization models.